Last year, Blackpool and other parts of Lancashire’s Fylde coast were rocked by two earthquakes. The tremors were only small, and geologists will tell you quakes of this size happen quite naturally about 10 times a month. But the tremors have placed the coastal resort at the epicentre of a new controversy because what stood out about these earthquakes is that they were not natural phenomena. They were caused as engineers tried to extract shale gas – methane – from beneath the Earth’s surface, using a technique called fracking.